$tu - 5tv - 4t + 5 = -8u + 9$ Solve for $t$.
Explanation: Combine constant terms on the right. $tu - 5tv - 4t + {5} = -8u + {9}$ $tu - 5tv - 4t = -8u + {4}$ Notice that all the terms on the left-hand side of the equation have $t$ in them. $1{t}u - 5{t}v - 4{t} = -8u + 4$ Factor out the $t$ ${t} \cdot \left( u - 5v - 4 \right) = -8u + 4$ Isolate the $t$ $t \cdot \left( {u - 5v - 4} \right) = -8u + 4$ $t = \dfrac{ -8u + 4 }{ {u - 5v - 4} }$ We can simplify this by multiplying the top and bottom by $-1$. $t= \dfrac{8u - 4}{-u + 5v + 4}$